puretic



Oct. 27, 1959 J c Re. 24,727

OSCILLATING SYSTEM FOR DERRICK BOOMS Original Filed July 2, 1957 2Sheets-Sheet 1 IIIHIH y IIIIIIIJVIIA INVENTOR 4442/0 J UEET/O Z W W.

ATTORNEY Oct. 27, 1959 M. J. PURETIC OSCILLATING SYSTEM FOR DERRICKBOOMS Original Filed July 2, 1957 2 Sheets-Sheet 2 United States PatentOfilice Re. 24,727 Reissued Oct. 27, 1959 OSCILLATIN G SYSTEM FORDERRICK BOOMS Mario J. Puretic, San Pedro, Calif.

Original No. 2,859,882, dated November 11, 1958, Serial No. 669,620,July 2, 1957. Application for reissue June 29, 1959, Serial No. 823,793

12 Claims. (Cl. 212-66) Matter enclosed in heavy brackets [J appears ll]the original patent but forms no part of this reissue specification;matter printed in italics indicates the additions made by reissue.

This invention relates to hoisting apparatus primarily for use onshipboard and more particularly to a mechanism for automaticallyproviding an oscillating movement to the boom of such hoisting apparatusin order to move the same back and forth through a predetermined arc,such swinging movement being continuous and automatic.

While the apparatus of this invention may be utilized in anyinstallation where it is desired to continuously and automaticallyoscillate the boom of a derrick through a predetermined arc, the primarypurpose of this invention is to provide an apparatus for use infacilitating fishing operations in which a relatively long net, commonlycalled a seine, must be hoisted from the water and stacked on the deckof the fishing vessel. Heretofore, it has been customary to hoist theseine from the water and to manually lay the same in folds on the deckof the vessel as the seine is lowered by the derrick, but since suchseines are relatively heavy, considerable manual exertion is required onthe part of several men and consequently, any apparatus which willperform this operation automatically thereby eliminating the necessityof manual operations will materially reduce the cost of such fishingoperation.

. It is accordingly an object of the invention to provide an automaticoscillating system for derrick booms which may be conveniently appliedto existing equipment without material modification thereof or which maybe conveniently and economically included during the manufacture of suchequipment.

A further object of the invention is the provision of an automaticoscillating system for derrick booms in which the arc through which theboom oscillates may be conveniently adjusted and with the center of suchoscillation disposed at any desired angular position.

A still further object of the invention is the provision of an automaticoscillating system for derrick booms in which fluid pressure may beutilized to swing a boom to and fro through a predetermined arc and overany desired portion of the deck of a vessel or the surface below theboom.

Another object of the invention is the provision of an automaticoscillating system for derrick booms in which fluid pressure may beutilized to swing a boom to and fro through a predetermined arc and overany desired portion of the deck of a vessel or the surface below theboom.

Another object of the invention is the provision of an automaticoscillating system for derrick booms in which double acting fluidpressure operated cylinders are utilized to swing the boom to and froand in which the operation of such cylinders are automaticallycontrolled by a simple reversing valve mechanism. i

A further object of the invention is the provision of an automaticoscillating system for derrick booms which may be conveniently andeconomically manufactured from readily available materials and whichwill materially reduce the cost of fishing operations.

A still further object of the invention is to provide means which may bemanually operated to swing a boom in the manner described herein.

Further objects and advantages of the invention will be apparent fromthe following description taken in conjunction with the accompanyingdrawings, wherein:

Fig. 1 is a top plan view showing a derrick incorporating theoscillating system of this invention and further showing the arrangementof the cables utilized to swing the derrick boom from one side to theother;

Fig. 2 a side elevational view showing a portion of a derrick mast andboom, together with the oscillating system of this invention and themanner in which the same is installed;

Fig. 3 a sectional View taken substantially on the line 33 of Fig. 2 andshowing the valve actuating lever shifting members disposed in positionto maintain the boom substantially in a fore and aft position;

Fig. 4 a sectional view taken substantially on the line 44 of Fig. 2 andshowing thevalve actuating lever shifting members disposed in positionto cause oscillation of the derrick boom through a predetermined arc andshowing in dotted lines the extreme position of the boom and shiftingmembers prior to reversal of the oscillating mechanism;

Fig. 5 a fragmentary sectional view taken substantially on the line 5-5of Fig. 4 and showing the mechanism utilized to lock the shiftingmembers in adjusted position; and

Fig. 6 a fragmentary sectional view taken substantially on the line 66of Fig. 4 and showing the yieldable actuating lever engaging means onthe shifting members.

With continued reference to the drawing, there is shown a derrick mast10 upon which may be mounted at any desired location a collar 11 whichserves to pivotally support a king pin 12 for movement about a verticalaxis. King pin 12 may be provided at the upper end thereof with spacedcars 13 and a pivot pin 14 extending through the cars 13 serves topivotally mount the lower end 15 of a boom 16 for movement about ahorizontal axis.

The boom 16 may be provided with lugs 17 and 18 extending from oppositesides thereof adjacent the lower end 15 and fluid pressure operatedcylinder 19 may be provided at the lower end with spaced cars 20 whichare received over the lug 17 and a fastening member 21 extending throughthe ears 2% and lug 17 serves to secure the cylinder 19 at the lower endto the boom 16. In a similar manner, a second fluid pressure operatedcylinder 22 may be provided with spaced ears 23 which are received overthe lug 18 and pivotally secured thereto by suitable fastening means 24in order to secure the cylinder 22 to the boom 16 adjacent the lower endthereof.

Cylinder 19 may be provided with a double acting piston 25 to which isconnected a ram 26 projecting from the upper end of the cylinder 19 andat the upper end of the ram 26 there is mounted a pulley 27. In asimilar manner, the cylinder 22 may be provided with a double actingpiston to which is attached a ram 28 extending from the upper end of thecylinder 22 and at the upper end of the ram 28 there is mounted a pulley29.

As best shown in Fig. 1, the boom 16 may be provided at the upper orhead end thereof with head pulleys 30 and 31 disposed on opposite sidesof the boom 16 and a flexible cable 32 of suitable material is trainedover the head pulley 30 and downwardly around the pulley 27 on the ram26 with the adjacent end 33 of the cable 32 being attached to the boom16 outwardly of the outermost point of travel of the ram 26. Theopposite end 34 of the cable 32 is secured to a fixed member 35, whichin the case of a marine installation, may be a part of the boat on whichthe apparatus is installed. In a similar manner, a flexible cable 36 istrained over the head pulley 31 and downwardly around pulley 29 on theram 28 with the adjacent end 37 of the cable 36 being attached to theboom 16 at a point outwardly of the outermost point of travel of the ram28. The opposite end 38 of the cable 36 is attached to a fixed member 39which as clearly shown in Fig. 1 is in alignment with the king pin 12and the fixed member 35 to which the cable 32 is attached.

A reversing control valve 40 of any suitable design may be convenientlymounted on a bracket 41 secured to the mast below the collar 11 and thecontrol valve 40 may be provided with upwardly extending spaced valveactuating levers 42 and 43. Actuating lever 42 may be provided with ahand engaging knob 44 and actuating lever 43 may be provided with a handengaging knob 45. Fluid pressure operated cylinder 19 may be connectedto the control valve 48 through suitable flexible conduits 46 and 47 andthe operation of cylinder 19 may be controlled by the actuating member42. In a similar manner, fluid pressure operated cylinder 22 may beconnected to the control valve 40 through suitable flexible conduits 48and 49 and cylinder 22 may be controlled by the valve actuating lever43. A fluid pressure supply conduit 50 may be connected to any suitablefluid pressure source, such as a pump and to the valve 40 and a fluidpressure discharge conduit 51 may also be connected to the control valve40 and to a fluid. pressure supply tank or sump to which the fluidpressure pump may be connected.

Since the fluid pressure operated cylinders 19 and 22 are double acting,it will be seen that upon actuation of the valve actuating levers 42 and43 in either direction that fluid pressure will be introduced to thecylinders 19 and 22 to either project the rams 26 and 28 therefrom or toretract such rams within the cylinders. As will be seen from aninspection of Fig. 1, retraction of the "ram 26 and projection of theram 28 will serve to shorten the cable 32 and, at the same time,lengthen the cable 36 thereby swinging the boom 16 toward the fixedmember 35 and operation of the rams 26 and 28 in the op- Tpositedirections will serve to swing the boom 16 in the opposite directiontoward the fixed member 39. The length of the are through which the boom16 moves will, of course, be controlled by the length of travel of therams 26 and 28 in the cylinders 19 and 22.

In order to provide automatic operating on the actuating levers 42 and43 to provide continuous automatic oscillation of the boom 16, asubstantially semi-circular plate 52 may be fixed to the king pin 12 bymeans of a set screw 53 or other suitable fastening means for movementwith the king pin 12 during swinging move- 1 ment of the boom 16. Theplate 52 may also be retained on the lower end of the king pin 12 bymeans of a nut or other suitable fastening means 54. Adjacent theperiphery of the semi-circular plate 52 there may be .provided anarcuate slot 55 and a suitable degree scale 56 may be provided on theplate 52 adjacent the slot 55. A substantially semi-circular opening 57is provided in the plate 52 and the actuating levers 42 and 43 of the reversing valve 40 project upwardly through the opening 57 to permit freeoscillating movement of the plate 52.

Opposed actuating lever shifting members 58 and 59 are disposed onopposite sides of the actuating levers 42 and 43 and the inner ends 60and 61 of the shifting members 58 'and 59 respectively are mounted forfree pivotal movement on. the king pin 12 above the semicircular plate52. Shifting member 58 is provided adjacent the outer end 62 thereofWith clamp means com and aft position.

prising a bolt 63 extending downwardly through the slot 55 in the plate52, there being provided at the lower end of the bolt 63 a head 64 and awasher 65 engaging the lower surface of the plate 52. A finger engagingknob 66 is threadedly received on the upper end of the bolt 63 andserves to clamp :the shifting member 58 in adjusted angular positionwith relation to the semi-circular plate 52. In a similar manner, theshifting member 59 is provided adjacent the outer end 67 thereof with abolt 68 extending through the slot 55 in the plate 52 and a fingerengaging knob 69 threadedly engaging the upper end of the bolt 68 servesto clamp the shifting member 59 in adjusted angular position withrelation to the semi-circular plate 52.

Shifting member 58 may be provided with actuating lever engaging means70 and 71, while shifting member 59 may be provided with actuating leverengaging means 72 and 73. Each of the actuating lever engaging means maybe similarly constructed and as best shown in Fig. '6, such means maycomprise a plunger 74 slidably received in a bore 75 in the shiftingmembers 58 and 59 and sliding movement of the plunger 74 may berestricted by a pin 76 disposed in a slot 77. Other means forrestricting movement of the plunger 74 may, of course, be employed ifdesired. The plunger 74 may be yieldably urged to outer position by acompression spring 78 disposed in the bore 75 and engaging the plunger74 and the tension of spring 78 may be conveniently controlled by ascrew threaded member 79 threadedly received in the shifting members 58and 59 and provided with a washer or other suitable means 80 engagingthe compression spring 78. The screw threaded member 79 may be providedwith a wrench receiving portion 81 to permit convenient adjustmentthereof.

In the operation of the apparatus of this invention, the shiftingmembers 58 and 59 may be set at any desired angular position, as shownin full lines in Fig. 4, and it may be assumed that the valve actuatinglevers 42 and 43 are in neutral position and the boom 16 in a fore It isalso to be assumed that fluid pressure is supplied in the valve 40through the conduit 50 and when it is desired to place the apparatus inoperation, the hand engaging knobs 44 and 45 on the actuating levers 42and 43 may be moved in one direction to introduce fluid pressure to thecylinders 19 and 22 thereby resulting in swinging movement of the boom16 in one direction. Assuming that the actuating levers 42 and 43.

are moved toward the shifting member 59 as viewedin Fig. 4, this willresult in movement of the boom 16 in a counter-clockwise direction untilthe actuating levers 42 and 43 are engaged by the means 72 and 73 on theshifting member 59 which will result in moving the ac- 'tuating levers42 and 43 to a position to reverse the place to reverse the swingingmovement of the boom .16 is shown in dotted lines in Fig. 4. Uponcompletion of the movement of the boom 16 in the opposite or clockwisedirection asshown in Fig. 4, the actuating lever engaging means 70 and71 on the shifting member '58 will engage the actuating levers 42 and'43 to move such levers to 'a position to again reverse the operation ofthe cylinders 19 and .22 thereby swinging the boom 16 in the "oppositedirection. This oscillating movement .of the boom 16 will automaticallycontinue until such time as the actuating levers 42 and 43 are manuallymoved to neutral position.

I It will therefore beseen that a seine suspended from the heador'uppe'r end of the boom .16 and being continuously hoisted'from thewater and lowered toward the: deck of the vessel will. be laid in foldson the deck :of the vessel and set in a uniformmanner.

When it is desiredto. secure the'boom 16 in a fore and "aft positionupon completion of fishing operations or for-any other purpose, theshifting members 58 and 59 may be disposed in the position shown in Fig.3 in which, the actuating levers 42 and 43 are simultaneously engaged bythe means 70 and 71, as well as the means 72 and 73 on both of theshifting members 58 and 59. This, of course, will operate to maintainthe levers 42 and 43 in neutral position.

Shifting members 58 and 59 adjusted as shown in Fig. 4, the swingingmovement of the boom 16 will be uniform about a fore and aft line, but,of course, if desired, the shifting members 58 and 59 may be adjusted toprovide a swinging movement centered about a line at an angle to thefore and aft line of the vessel.

It will, therefore, be seen that the apparatus of this invention willoperate to efiiciently stack a seine on the deck of a vessel in folds ofany desired length and will thereby eliminate the necessity of manualhandling of the net during recovery thereof from the water therebymaterially reducing the cost of fishing operations.

While the apparatus of this invention has been described primarily foruse on a fishing vessel, nevertheless, it will be obvious that the samemay be utilized for any installation where a continuous automatic ormanual oscillation of the boom of a derrick is required or advantageousand the apparatus of this invention is of such nature, that the same maybe conveniently installed on any existing derrick installation or, ofcourse, may be incorporated in new installations.

It will be obvious to those skilled in the art that various changes maybe made in the invention without departing from the spirit and scopethereof and therefore the invention is not limited by that which isshown in the drawing and described in the specification, but only asindicated in the appended claims.

What is claimed is:

1. An automatic oscillating system for derrick booms, said systemcomprising a king pin mounted for pivotal movement about a verticalaxis, a boom pivotally connected at the lower end to said king pin formovement about a horizontal axis, a pair of double acting fluid pressurecylinders mounted on opposite sides of said boom adjacent the lower end,a ram projecting from the upper end of each cylinder, a pulley on theupper end of each ram, a pair of head pulleys secured to the upper endof said boom on opposite sides, a pair of cables trained over said headpulleys and around the pulleys on said ram with the adjacent ends ofsaid cables fixed to said boom outwardly of the outermost point oftravel of said rams, the opposite ends of said cables being fixed attransversely spaced points in alignment with said king pin, a reversingcontrol valve for each cylinder, conduits connecting said cylinders andsaid valves, a fluid pressure supply conduit and a fluid pressuredischarge conduit connected to said valves, an actuating lever on eachvalve, a substantially semi-circular plate fixed to said king pin formovement therewith, an arcuate slot in said plate adjacent theperiphery, a substantially semi-circular opening in said plate throughwhich said actuating levers project, opposed actuating lever shiftingmembers disposed on opposite sides of said actuating levers, saidmembers being mounted at one end for free pivotal movement on said kingpin, clamp means at the opposite end of each member extending throughsaid slot for fixing each member in adjusted angular position andyieldable .actuating lever engaging means on each member whereby saidlevers and control valves will be periodically actuated to alternatelyconnect said fluid pressure supply conduit to said cylinders to lengthenand shorten said cables thereby continuously and automatically swingingsaid boom back and forth through an are determined by the position ofsaid members on said plate.

2. An automatic oscillating system for derrick booms, said systemcomprising a king pin mounted for pivotal movement about a verticalaxis, a boom pivotally connected at the lower end to said king pin formovement about a horizontal axis, a pair of double acting fluid pressurecylinders mounted on opposite sides of said boom adjacent the lower end,a ram projecting from the upper end of each cylinder, a pulley on theupper end of each ram, a pair of head pulleys secured to the upper endof said boom on opposite sides, a pair of cables trained over said headpulleys and around the pulleys on said rams with the adjacent ends ofsaid cables fixed to said boom outwardly of the outermost point oftravel of said rams, the opposite ends of said cablesbeing fixed attransversely spaced points in alignment with said king pin, a reversingcontrol valve for each cylinder, conduits connecting said cylinders andsaid valves, 3. fluid pressure supply conduit and a fluid pressuredischarge conduit connected to said valves, an actuating lever on eachvalve, a substantially semi-circular plate fixed to said king pin formovement therewith, an arcuate slot in said plate, a substantiallysemi-circular opening in said plate through which said actuating leversproject, opposed actuating lever shifting members disposed on oppositesides of said actuating levers, said members being mounted at one endfor free pivotal movement on said king pin, clamp means at the oppositeend of each member extending through said slot for fixing each member inadjusted angular position and actuating lever engaging means on eachmember whereby said levers and control valves will be periodicallyactuated to alternately connect said fluid pressure supply conduit tosaid cylinders to lengthen and-shorten said cables thereby continuouslyand automatically swinging said boom back and forth through an aredetermined by the position of said members on said plate.

3. An automatic oscillating system for derrick booms, said systemcomprising a king pin mounted for pivotal movement about a verticalaxis, a boom connected at the lower end to said king pin, a pair ofdouble acting fluid pressure cylinders mounted on opposite sides of saidboom adjacent the lower end, a ram projecting from the upper end of eachcylinder, a pulley on the upper end of each ram, a pair of head pulleyssecured to the upper end of said boom on opposite sides, a pair ofcables trained over said head pulleys and around the pulleys on saidrams with the adjacent ends of said cables fixed to said boom outwardlyof the outermost point of travel of said rams, the opposite ends of saidcables being fixed at transversely spaced points in alignment with saidking pin, a reversing control valve for each cylinder, conduitsconnecting said cylinders and said valves, a fluid pressure supplyconduit and a fluid pressure discharge conduit connected to said valves,an actuating lever on each valve, a substantially semi-circular platefixed to said king pin for movement therewith, an arcuate slot in saidplate, a substantially semi-circular opening in said plate through whichsaid actuating levers project, opposed actuating lever shitting membersdisposed on opposite sides of said actuating levers, said members beingmounted at one end for free pivotal movement on said king pin, clampmeans at the opposite end of each member extending through said slot forfixing each member in adjusted angular position and actuating leverengaging means on each member whereby said levers and control valveswill be periodically actuated to alternately connect said fluid pressuresupply conduit to said cylinders to lengthen and shorten said cablesthereby continuously and automatically swinging said boom back and forththrough an are determined by the position of said members on said plate.

4. An automatic oscillating system for derrick booms, said systemcomprising a king pin mounted for pivotal movement about a verticalaxis, a boom connected at the lower end to said king pin, a pair ofdouble acting fluid pressure cylinders mounted on opposite sides of saidboom adjacent the lower end, a ram projecting from the upper end of eachcylinder, a pulley on the upper end of each ram, a pair of head pulleyssecured to the upper end of said boom on opposite sides, a pair ofcables trained over said head pulleys and around the pulleys on saidrams with the adjacent ends of said cables fixed to said boom outwardlyof the outermost point of travel of said rams, the opposite ends of saidcables being fixed at transversely spaced points, a reversing controlvalve for each cylinder, conduits connecting said cylinders and saidvalves, a fluid pressure supply conduit and a fluid pressure dischargeconduit connected to said valves, an actuating lever on each valve, asubstantially semicircular plate fixed to said king pin for movementtherewith, an arcuate slot in said plate, a substantially semicircularopening in said plate through which said actuating levers project,opposed actuating lever shifting members disposed on opposite sides ofsaid actuating levers, said members being mounted at one end for freepivotal movement on said king pin, clamp means at the opposite ends ofeach member extending through said slot for fixing each member inadjusted angular position and actuating lever engaging means on eachmember whereby said levers and control valves will be periodicallyactuated to alternately connect said fluid pressure supply conduit tosaid cylinders to lengthen and shorten said cables thereby continuouslyand automatically swinging said boom back and forth through an aredetermined by the position of said members on said plate.

5. An automatic oscillating system for derrick booms, said systemcomprising a king pin mounted for pivotal movement about a verticalaxis, a boom connected at the lower end to said king pin, a pair ofdouble acting fluid pressure cylinders mounted on opposite sides of saidboom adjacent the lower end, a ram projecting from the upper end of eachcylinder, a pulley on the upper end of each ram, a pair of head pulleyssecured to the upper end of said boom on opposite sides, a pair ofcables trained over said head pulleys and around the pulleys on saidrams with the adjacent ends of said cables fixed to said boom outwardlyof the outermost point of travel of said rams, the opposite ends of saidcables being fixed at transversely spaced points, a reversing controlvalve for each cylinder, conduits connecting said cylinders and saidvalves, a fluid pressure supply conduit and a fluid pressure dischargeconduit connected to said valves, an actuating lever on each valve, aplate fixed to said king ,pin for movement therewith, an arcuate slot insaid plate, a subtsantially semi-circular opening in said plate throughwhich said actuating levers project, opposed actuating lever shiftingmembers disposed on opposite sides of said actuating levers, saidmembers being mounted at one end for free pivotal movement of said kingpin, clamp means at the opposite end of each member extending 'throughsaid slot for fixing each member in adjusted angular position andactuating lever engaging means on each member whereby said levers andcontrol valves will be periodically actuated to alternately connect saidfluid pressure supply conduit to said cylinders to lengthen and shortensaid cables thereby continuously and automatically swinging said boom.back and forth through an are determined by the position of said memberson said plate.

6. An automatic oscillating system for derrick booms, said systemcomprising a king pin mounted for pivotal movement about a verticalaxis, a boom connected at the lower end to said king pin, a pair ofdouble acting fluid pressure cylinders mounted on opposite sides of saidboom adjacent the lower end, a ram projecting from the upper end of eachcylinder, a pulley on the upper end of each ram, a pair of head pulleyssecured to said boom on opposite sides, a pair of cables trained oversaid head pulleys and around the pulleys on said rams with the adjacentends of said cables fixed to said boom outwardly of the outermost pointof travel of said rams, ithe opposite ends of said cables being hired attransversely spaced points, a reversing control valve for each cylinder,conduits connecting said cylinders and said valves, afluid pressuresupply conduit and a fluid pressure f8 discharge conduit connected tosaid valves, "an "actuating lever on each valve, a plate fixed to saidking pin'for movement therewith, an arcuate slot in said plate, asubstantially semi-circular opening in said plate through which saidactuating levers project, opposed actuating levers shifting membersdisposed on opposite sides of said actuating levers, said members beingmounted at one end for free pivotal movement on said king pin, clampmeans at the opposite end of each member extending through said slot forfixing each member in adjusted angular position and actuating leverengaging means on each member whereby said levers and controlvalves'will be periodically actuated to alternately connect said fluidpressure supply conduit to said cylinders to lengthen and shorten saidcables thereby continuously and automatically swinging said boom backand forth through an are determined by the position of said members onsaid plate.

7. An automatic oscillating system for derrick booms, said systemcomprising a king pin mounted for pivotal movement about a verticalaxis, a boom connected at the lower end to said king pin, a pair ofdouble acting fluid pressure cylinders mounted on opposite sides of saidboom adjacent the lower end, a ram projecting from the upper end of eachcylinder, a pulley on the upper end of each ram, a pair of head pulleyssecured to said boom on opposite sides, a pair of cables trained oversaid head pulleys and around the pulleys on said rams with the adjacentends of said cables fixed to said boom, the opposite ends of said cablesbeing fixed at transversely spaced points, a reversing control valve foreach cylinder, conduits connecting said cylinders and said valves, afluid pressure supply conduit and a fluid pressure discharge conduitconnected to said valves, an actuating lever on each valve, a platefixed to said kingpin for movement therewith, anarcuate slot in saidplate, a substantially semi-circular opening in saidplate through whichsaid actuating levers project, opposed actuating lever shifting membersdisposed on opposite sides of said actuating levers, said members beingmounted at one end for free pivotal movement on said king pin, clampmeans at the opposite end of each member extending through said slot forfixing each member in adjusted angular position and actuating leverengaging means on each member whereby said levers and control valveswill be periodically actuated to ultimately connect said fluid pressuresupply conduit to said cylinders to lengthen and shorten said cablesthereby continuously and automatically swinging said boom back and forththrough an are determined by the position of said member on said plate.

8. An automatic oscillating system for derrick'booms, said systemcomprising a kingpin mounted for pivotal movement about a vertical axis,a boom connected at the lower end to said king pin, a pair of doubleacting fluid pressure cylinders mounted on opposite sides of said boomadjacent the lower end, a ram projecting from the upper end of eachcylinder, a pulley on the upper end of each ram, a pair of head pulleyssecured to said boom on opposite sides, a pair of cables trained oversaid head pulleys and around the pulleys on said rams with the adjacentends of said cables fixed to said boom, the opposite ends of said cablesbeing fixed at transversely spaced points, a reversing control valve foreach cylinder, conduits connecting said cylinders and said valves, afluid pressure supply conduit and a fluid pressure discharge ccnduitconnected to said valves, an actuating lever on each valve, a platefixed to said king pin for movement therewith, an arcuate slot in saidplate, an opening in said plate through which said actuating leversproject, opposed actuating lever shifting members disposed on oppositesides of said actuating levers, said members being mounted at one endfor free pivotal movement on said king pin, clamp means on each memberextending through said slot for fixing each member in adjusted angularposition and actuating lever engaging means on each member whereby saidlevers and control valves will be periodically actuated to alternatelyconnect said fluid pressure supply conduit to said cylinders to lengthenand shorten said cables thereby continuously and automatically swingingsaid boom back and forth through an are determined by the position ofsaid members on said plate.

9. An automatic oscillating system for derrick booms, said systemcomprising a king pin mounted for pivotal movement about a verticalaxis, a boom connected at the lower end to said king pin, a pair ofdouble acting fluid pressure cylinders mounted on said boom adjacent thelower end, a ram projecting from the upper end of each cylinder, apulley on the upper end of each ram, a pair of head pulleys secured tosaid boom, a pair of cables trained over said head pulleys and aroundthe pulleys on said rams with the adjacent ends of said cables fixed tosaid boom, the opposite ends of said cables being fixed at transverselyspaced points on opposite sides of said boom, a reversing control valvefor each cylinder, con'duits connecting said cylinders and said valves,a fluid pressure supply conduit and a fluid pressure discharge conduitconnected to said valves, an actuating lever on said valves, a platefixed to said king pin for movement therewith, an arcuate slot in saidplate, an opening in said plate through which said actuating leversproject, opposed actuating lever shifting members disposed on oppositesides of said actuating levers, said members being mounted at one endfor free pivotal movement on said king pin, clamp means on each memberextending through said slot for fixing each member in adjusted angularposition and actuating lever engaging means on each member whereby saidlevers and control valves will be actuated to alternately connect saidfluid pressure supply conduit to said cylinders, to lengthen and shortensaid cables thereby continuously and automatically swinging said boomback and forth through an are determined by the position of said memberson said plate.

10. An automatic oscillating system for derrick booms, said systemcomprising a king pin mounted for pivotal movement about a verticalaxis, a boom connected at the lower end to said king pin, a pair ofdouble acting fluid pressure cylinders mounted on said boom adjacent thelower end, a ram projecting from the upper end of each cylinder, apulley on the upper end of each ram, a pair of head pulleys secured tosaid boom, a pair of cables trained over said head pulleys and aroundthe pulleys on said rams with the adjacent ends of said cables fixed tosaid boo-m, the opposite ends of said cables being fixed at transverselyspaced points on opposite sides of said boom, a reversing control valvefor each cylinder, conduits connecting said cylinders and said valves, afluid pressure supply conduit and a fluid pressure discharge conduitconnected to said valves, an actuating lever on each valve, a platefixed to said king pin for movement therewith, an arcuate slot in saidplate, an opening in said plate through which said actuating leversproject, opposed actuating lever shifting members disposed on oppositesides of said actuating levers, said members being mounted at one endfor free pivotal movement on said king pin and clamp means on eachmember extending through said slot for fixing each member in adjustedangular position whereby said levers and control valves will beperiodically actuated to alternately connect said fluid pressure supplyconduit to said cylinders, to lengthen and shorten said cables therebycontinuously and automatically swinging said boom back and forth throughan are determined by the position of said members on said plate.

11. An oscillating system for derrick booms, said system comprising: acollar adapted to be affixed around a ships mast, said collar having acylindrical bore therein to secure the lower cylindrical portion of aking pin mounted for pivotal movement about a vertical axis, the upperend of said king pin begin provided with spaced cars, a boom connectedat its lower end to the ears-of said king pin by a horizontallyextending pin, a pair of fluid pressure cylinders mounted on said boom,a ram projecting from an end of each of said cylinders, a pulley on theend of each ram, a pair of pulleys secured to the outer end of saidboom, a pair of cables trained over said last-named pulleys and aroundsaid pulleys on said rams with the adjacent ends of said cables fixed tosaid boom, the opposite ends of said cables being fixed at transverselyspaced points on opposite sides of said boom, a bracket adapted to besecured to said mast and a reversing control valve for each cylindermounted on said bracket, conduits connecting said cylinders and saidvalves, a fluid pressure supply conduit and a fluid pressure dischargeconduit connected to said valves, each of said control valves beingprovided with an upwardly extending lever operable manually forperiodically shifting said control valves to alternately connect saidfluid pressure supply conduit to said cylinders to length and shortensaid cables thereby swinging said boom back and forth.

12. An oscillating system for derrick booms, said system comprising: acollar adapted to be affixed around a ships mast, said collar having acylindrical bore therein to receive the lower cylindrical portion of aking pin 7 mounted for pivotal movement about a vertical axis, a

boom connected at its lower end to the ears of said king pin by ahorizontally extending pin, a pair of fluid pressure cylinders mountedon said boom, a ram projecting from an end of each said cylinders, apulley on the end of each ram, a pair of pulleys secured to the outerend of said boom, a pair of cables trained over said lastnamed pulleysand around said pulleys on said rams with the adjacent ends of saidcables fixed to said boom at points spaced rearwardly of the pulleys onsaid rams, a bracket adapted to be secured to said mast and a reversingcontrol valve for 'each cylinder mounted on said bracket, conduitsconnecting said cylinders and said valves, a fluid pressure supplyconduit and a fluid pressure discharge conduit connected to said valves,each of said control valves being provided with an upwardly extendinglever operable manually for periodically shifting said control valves toalternately connect said fluid pressure supply conduit to said cylindersto lengthen and shorten said cables thereby swinging said boom back andforth.

References Cited in the file of this patent or the original patentUNITED STATES PATENTS 400,798 Russell Apr. 2, 1889 497,216 Rogers May 9,1893 665,684 Hctlesaeter Jan. 8, 1901 2,021,066 Huxford Nov. 12, 1935

